JPH03257051A - Multimode spherical hydraulic cement composition - Google Patents

Abstract

PURPOSE:To obtain a cement product which is excellent in water resistance and fire resistance and also has high flexural strength by blending a working treatment additive with spherical hydraulic cement having the particle size distribution of a multimode. CONSTITUTION:Spherical hydraulic cement composition having the constitution of particle size distribution of a multimode is obtained by adding at least one kind selected from among a water-dispersive working treatment additive, a water-soluble working treatment additive, a water-nondispersive working treatment additive and a water-nonsoluble working treatment additive at 0.1-10.0 pts.wt. for 100 pts.wt. spherical hydraulic cement of the multimode. in the above- mentioned spherical hydraulic cement composition of the multimode, furthermore, water is added at the rate of about 30 pts.wt. for 100 pts.wt. spherical hydraulic cement of the multimode. Further, fine aggregate, coarse aggregate, a filler and fiber, etc., are blended as the additive in accordance with necessity. As the working treatment additives e.g. cellulose ether derivatives, a hydrolyzed vinyl acetate (co)polymer, polyethylene and acrylic resin, etc., are shown.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" This invention relates to a multimodal spherical hydraulic cement composition that can be molded in close packing by mixing under low water-to-cement ratio and shear stress. , relates to a multimodal spherical hydraulic cement composition, which enables the production of dense cement products with high bending strength.

``Prior Art'' Conventionally, in order to produce cement such as Portland cement, raw materials are pulverized and fired in a rotary kiln, and the resulting cement clinker is then rapidly cooled with air. Then, gypsum powder is added to the cooled cement clinker, and this is further pulverized again using a tube mill or the like to obtain cement of a desired particle size.

By the way, the Portland cement obtained in this way generally has a water-cement ratio of about 60%, a mortar compressive strength of about 400 kg/am' at 4 weeks of age, and a bending strength of 50 to 70 kg/c+n'' ( 5~7MPa)
I could only get so much.

``Invention or problem to be solved'' In order to solve the above-mentioned shortcomings, the bending strength is increased to 50 MPa or more by minimizing the voids in the hardened cement structure using methods such as high shear mixing or calendar molding. A technique for obtaining a hardened hydraulic cementitious material with high toughness has been provided. (JP-A-56-9256, JP-A-56-14465, JP-A-56-84349) However, the hardened cement products produced by these techniques have poor water resistance and also contain a large amount of additives. Therefore, it has a fatal drawback of being inferior in fire resistance and therefore not being a noncombustible material. Therefore, it has been extremely difficult to put hydraulic cementitious materials based on these technologies into practical use.

This invention was made in view of the above circumstances, and has water resistance,
The object of the present invention is to provide a multi-mode spherical hydraulic cement composition that is excellent in fire resistance and can provide a cement product having high bending strength.

"Means for Solving the Problems" In the multimodal spherical hydraulic cement composition of the present invention, in the spherical hydraulic cement composition having a multimodal particle size distribution configuration, based on 100 parts by weight of the spherical hydraulic cement, 0.1 to 10.0 parts by weight of at least one of water-dispersible processing additives, water-soluble processing additives, non-water-dispersible processing additives, and non-water-soluble processing additives are added. This was the solution to the above problem.

Hereinafter, the multimode spherical hydraulic cement composition of the present invention will be explained in detail.

First, to explain about spherical hydraulic cement, spherical hydraulic cement has spherical particles, for example, the following ■ ~
It is manufactured by the method (2).

(2) A method of obtaining cement by passing cement clinker through a high-temperature flame to make it melt or semi-molten, then cooling it, and then adding gypsum powder.

■ A method in which a mixture of cement clinker and gypsum powder is passed through a high-temperature flame to form a molten or semi-molten state, which is then cooled.

■ Spherical gypsum made by passing cement talin force through a high-temperature flame to melt or semi-melt it, then cooling it, and then making it by the same method as the cement clinker or by a conventionally known spheroidizing treatment method. Method obtained by adding powder.

■A method in which cement clinker or a mixture of cement clinker and gypsum powder is spheroidized by an impact method in a high-speed air stream.

In other words, gypsum, which is naturally added as cement, may be added after the spheroidizing treatment of the cement talin, or may be spheroidized together with the cement talin car, or even gypsum may be spheroidized separately from the cement talin car. It may be mixed with treated and later spheronized cement clinker.

To elaborate on method (■) above, in order to obtain spherical hydraulic cement using this method, first the raw materials are crushed and fired in a rotary kiln in the same way as in the conventional method, and then the obtained cement talinker is quenched with air. . Then, gypsum is added to the cooled cement and pulverized again using a tube mill or the like to adjust the particle size to a desired size. Here, finally, the cement talin force of the mode classified as below is passed through the high temperature flame,
The particle size of the multimode spherical hydraulic cement obtained by subsequently adding spherical gypsum is, for example, when the multimode is two modes, the particle size of the coarser mode is 60 to 110.
The cement particles have a particle diameter of 1 to 10 microns in the mode where the particles are finer. To explain in more detail, the cement tarinker to be put into the high temperature flame of the present invention is classified by a known method such as classification to reduce the particle size to 65.
~120μ shoulder cement talin force-particles and particle size 1~
Cement tarinker particles of 20μ order are obtained, respectively.

In this case, cement clinker particles with a particle size of 65 to 12
The reason for obtaining the 0μ shoulder and 1 to 20μ shoulder is that these cement clinker particles are passed through a high-temperature flame and spheroidized, which reduces the apparent average particle size and reduces the final size. This is because the particle diameters of the spherical cement obtained by adding spherical gypsum to the cement particles are 60 to 110 microns and 1 to 10 microns. The cement tarinker particles of each particle size classified and produced in this way are, for example, 50% by weight or more of the particles in the coarser mode, and 50% by weight or more of the particles in the finer mode. It is blended so that it accounts for 5% by weight or more of the total weight.

Next, prepare a flame generator that uses flammable gases such as propane, butane, propylene, acetone, and hydrogen, liquid fuels such as heavy oil and light oil, or petroleum, and even solid fuels such as oil coke. Generates flame. Next, a predetermined amount of cement particles, the particle size of which has been adjusted as described above, is fed into the flame to melt or semi-melt it, and it is further cooled.

Here, if necessary, cement clinker particles with a particle size outside the mode are added to the cement clinker particles after particle adjustment and subjected to spheroidization treatment, or in that case, the amount of particles added is as follows: For example, it is preferable to add 20% or less of the total weight of particles of intermediate particle size in adjacent modes, or 20% or less of the total weight of particles of particle size of each of the adjacent modes. ~10μ
In the example of two modes, it is preferable that the total weight of particles outside the range of these two modes is 20% or less of the total weight.

When the cement clinker particles are passed through the flame in this manner, the molten or semi-molten cement clinker particles become spheroidized by their surface tension.

The flame temperature here varies depending on the type of cement clinker, but it is necessary to be at least 1,300°C or higher, preferably 1,500°C or higher; if it is lower than 1,300°C, the cement clinker particles are fully molten or semi-molten. Therefore, the cement talin particles do not become sufficiently spherical, which is undesirable. Further, the residence time in the flame is preferably about 0.01 to 0.05 seconds. In addition, when using a highly gifted fuel as the fuel for the above-mentioned flame generator, it is necessary to adjust the blend of cement raw materials in advance so that the cement components become target components.

Thereafter, about 0 to 5 parts by weight of gypsum powder is added to 100 parts by weight of the obtained spherical cement clinker, and the desired hydraulic speed is adjusted to obtain a spherical hydraulic cement.

In addition, the particle size of the gypsum powder should be adjusted in advance to match the particle size of each mode of cement talin force - particles.
This is preferable in order to improve the close packing and fluidity of the resulting spherical hydraulic cement, and also to improve the bending strength of the hardened cement product obtained therefrom.

Also, the difference from the example of method ■ or method ■ above is that
The point is that not only cement clinker particles alone but also a mixture of cement clinker particles whose particle size has been adjusted and gypsum powder whose particle size has also been adjusted are fed into the flame of a flame generator and fired and melted. In this case, by taking the cement out of the flame and cooling it, spherical cement can be obtained without adding gypsum powder. Here, the flame temperature is 1 as in the above example.
It is said to be over 3000C. Further, in this case, it is preferable that the amount of gypsum powder mixed into the cement tarinker be larger than in the above example, since a part of the gypsum powder decomposes at temperatures above 1300°C.

Also, the difference between method ■ above and method example ■ is as follows:
The point is that spherical gypsum powder is used as the gypsum powder added to the obtained spherical cement clinker. Here, the spherical gypsum powder used is one that has been passed through a high-temperature flame as in the case of cement clinker, or one that has been subjected to a spheroidization process during the gypsum manufacturing process.

In addition, method (■) above is a completely different method from methods (■ to ■) in which the angular parts of the clinker are simply shaved off by the impact of high-speed airflow without exposing the cement clinker to the flame, resulting in spherical cement particles. This is the way to obtain. As described above, the method for producing spherical hydraulic cement clinker or cement according to the present invention is not limited to the above-mentioned method of passing through a high-temperature flame. may be subjected to spheroidization treatment using a known method.

Since the spherical hydraulic cements obtained in this way are all spherical, there is less frictional resistance between the particles, and therefore they have a larger flow value than conventional cements at the same water-cement ratio. Become. Since this improves fluidity and filling properties, the strength of the hardened cement body after hardening is higher than that of conventional cement.

Next, the multi-mode formation of the upper three-dimensional spherical hydraulic cement will be explained.

Here, ``multimodal j'' means that there are two or more distinguishable bands, or modes, of grain size in the distribution pattern, with intermediate grains between adjacent major bands (i.e., modes). This means that the particle size distribution is present in only a very small proportion throughout the mode and is therefore not substantially continuous throughout the particle size distribution. It is sufficient that the total weight of the particles in the diameter does not exceed 20% of the total weight of the particles in adjacent major bands (i.e. modes).Also, as for multimode, bimodal is preferable. , 3 modes may be advantageous,
Furthermore, four modes may be used. However, even if the number of modes is increased beyond this, there is little effect to be obtained, and it is economically disadvantageous in terms of additional costs and labor.

A quantitative example of the desired particle size distribution of the spherical hydraulic cement is as follows regarding the bimodal distribution.

As a first general guideline, the ratio of the weight average particle sizes of the particles in each band (mode) should be as widely separated as practical. The reason for this is that it facilitates the achievement of desired properties in cement products made from the hydraulic cement, such as improved flexural strength. Therefore, if the weight average particle size of the coarser mode is Dl and the weight average particle size of the finer mode is , then the ratio of D, ·D, is preferably 2 or more, more preferably The number is 10 or more, more preferably 20-40.

As a second guideline, it is preferable that the range of particle sizes in each mode be narrower than wider. That is, it is preferable that the particle size range for each mode is as narrow as technically and economically possible.

Particularly useful compositions of spherical hydraulic cements with a bimodal distribution include those having the following particle sizes and weight ratios.

(a) The particle size is between 60 and 110μ, and the weight ratio is 50% of the total.
% by weight or more, preferably 70-90% by weight, (b) particle size of 1-10μ! (C) The above (a) and (b)
20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less of the total particle size.

In addition, in the particle size ranges of (a) and (b) above,
By narrowing the particle size range, it is possible to improve close packing. That is, for example, in (a), 70 to 90μ distributed with a width of about 20 to 25μ
The opposite particle size range is preferred, and in (b) a particle size range of 4 to 8 μl distributed with a width of about 5 μl is preferred.

By applying the first and second guidelines, useful compositions can be defined outside of the compositions consisting of the specific particle size ranges (a), (b) and (C) above. It should be noted that the optimum composition depends, to a certain extent, on the properties of the spherical hydraulic cement used, its economics (in particular the economics of specifying the desired dimensions and performing the classification), and the degree to which it affects the maximum strength of the hardened cement product. It depends on whether it is required to get as close as possible.

For the 3rd mode, guidelines similar to those for the 2nd mode can be applied. If the weight average particle diameters of the three modes, that is, coarse, intermediate, and fine modes, are DD and , then the ratio of D, + D, and ・D3 is the above 2.
In the heavy mode distribution: D.

It should satisfy the specified ratio.

Of course, it may not be practical to make both D, +D, and .D3 the same. Therefore, the two may be quite different from each other, or at least one of them may be within a preferable range. Furthermore, the effect obtained by narrowing the particle size range of each mode in a two-mode distribution is the same in a three-mode distribution, and therefore it is still preferable to narrow the particle size range of each mode. .

Particularly useful compositions of spherical hydraulic cements with a trimodal distribution include those having the following particle sizes and weight ratios.

(a) The particle size is 100 to 150μ and the weight ratio is 50% of the total.
% by weight or more, preferably 70 to 90% by weight, (b) particle size of 7 to 12 μg and a weight ratio of 1% by weight or more of the total, preferably 10 to 30% by weight, (c) particle size of 0.5 - 2μ scraps weigh 1% or more of the total weight, preferably 3 to 8% by weight
.

Multi-mode distribution adjustment of spherical hydraulic cement can be carried out by classifying cement clinker particles in advance before spheroidizing them as described above, and mixing them in a desired weight ratio. The cement clinker particles are spheronized and then classified by sieving or any other conventional means to obtain particles in the desired size range, and then mixed in the desired weight ratio. It's okay. Here, the reason why a classification operation is required to adjust the multimode distribution is because conventional granular hydraulic cement is generally manufactured by first grinding a coarse material into a powder. This is because the particles have a very wide particle size distribution. That is, conventionally commercially available hydraulic cements typically have a particle size distribution that spans a wide, substantially continuous particle size band (eg, from 1 μm or more to about 150 μm coarse). Of course, among the cement particles separated by the classification operation, those having a particle size larger than a desired value can be adjusted to the desired particle size by pulverization treatment or remelting treatment.

Then, 30 parts by weight or less, preferably 15 parts by weight or less, more preferably 7 parts by weight or less of water is added to 100 parts by weight of the multimode spherical hydraulic cement thus obtained. Here, in the present invention, the amount of water added is 30 parts by weight or less, or the amount of water added can be reduced by using the spheroidized hydraulic cement of the present invention, and the amount of water added is 30 parts by weight or less. The amount can be reduced to preferably 0.1 to 5.0 parts by weight, more preferably 0.1 to 3.0 parts by weight, and thereby a hydraulic cement hardened product with high bending strength can be obtained. . Furthermore, with respect to 100 parts by weight of the multimode spherical hydraulic cement, at least one of a water-dispersible processing additive, a water-soluble processing additive, a non-water-dispersible processing additive, and a water-insoluble processing additive is added. 1 to 10.0 parts by weight of one type, preferably 01 to 50 parts by weight
The multimodal spherical water of the present invention can be prepared by adding parts by weight, more preferably 0.1 to 30 parts by weight, and further adding fine aggregate, coarse aggregate, filler, and fiber as additives as necessary. A hard cement composition is obtained.

The amount of the processing additive added is set at 01 to 100 parts by weight because if it is less than 0.1 part by weight, the effect of adding it will not be obtained substantially, and if it exceeds 10.0 parts by weight, This is because the water resistance and fire resistance of the hardened product (cement product) that is formed is undesirable. Further, in the present invention, the amount of the processing additive added is 0.1 to 10.0 parts by weight, but the use of the spheroidized hydraulic cement of the present invention and its polymorphism make it possible to add the processing additive. The amount can be reduced from 0.1 to 10.0 parts by weight, preferably from 0.1 to 10.0 parts by weight.
By reducing the amount added to 5.0 parts by weight, more preferably from 0.1 to 30 parts by weight, a hydraulic cement hardened product with high bending strength can be obtained. Therefore, the cement hardened products obtained from the multimode spherical hydraulic cement of the present invention have a much higher bending strength than conventional products. Cement hardened products are new materials that have never existed before, and are not only cement products, but also revolutionary new materials that can replace materials such as plastics, wood, steel, and non-ferrous metals (aluminum).

Here, the above-mentioned water-dispersible processing additives include: (1) cellulose ether derivatives (eg, alkylhydrokine alkylcellulose ether);

■Cellulose esters (e.g. nioxypropyl methylcellulose).

(1) Amide-substituted polymers (eg, acrylamide, methacrylamide polymers or copolymers thereof) (2) Derivatives of polyalkylene oxides (eg, polyalkylene oxides, polyalkylene glycols with a molecular weight of 10,000 or more, alcohols, polyalfoxy derivatives of phenol, lin, etc.).

■ Well-known types of sulfonated substances for imparting solubility sulfonated 'RL examples; lignosulfnates and sulfonated naphthalene salts ■ Polyols (e.g. glycerol, alkylene glycols, polyalkylene glycols) are preferably used. It will be done.

Further, as the water-soluble processing additive, 1) a hydrolyzed vinyl acetate polymer or a copolymer thereof, and 2) a hydrolyzed polyvinyl acetate polymer or a copolymer thereof are preferably used.

Here, the degree of hydrolysis of the vinyl acetate polymer or copolymer thereof is preferably at least 50%, and the degree of hydrolysis of the vinyl acetate polymer or copolymer thereof is preferably at least 50%. A little (even 70~
Preferably, it is 90%.

In addition, as the non-water dispersible or water-insoluble processing additives, polyethylene, fluororesin, boss styrene,
Synthetic resins such as phenol, polyvinyl chloride, polypropylene, acrylic, polyvinylidene chloride, epoxy, polyaramid, and furan are preferably used.

Furthermore, among the above additives, fine aggregates, coarse aggregates, and fillers include: (1) silica in various forms (eg, sand, quartz sand, fine amorphous warping force [fuming silica]); (2) gravel.

■Olivine.

■Titania (e.g. pigment edge grade titania).

■Slate powder etc. are suitably used.Fibers include: ■Organic fibers such as nylon, Tetron, acrylic, propylene, cellulose, raw silk, acetate, aramid fibers, etc.;■Glass fibers such as steel fibers and alkali-resistant glass fibers; Ceramic fibers such as silicon carbide fibers, inorganic fibers such as rock wool, and carbon fibers are preferably used.

In addition, when adding the above-mentioned water-dispersible processing additives or water-soluble processing additives to prepare a multimode spherical hydraulic cement composition, these additives are used in the form of an aqueous solution or aqueous dispersion. or preferable, in which case,
Of course, the amount of water in which these additives are dissolved or dispersed must also be converted into the amount of water added to the multimode spherical hydraulic cement.

In addition, regarding the addition of non-water dispersible or water-insoluble processing additives, conventionally known resin concrete technology,
The use of synthetic resins for impregnated concrete technology allows for uniform incorporation into multimodal spherical hydraulic cements.

Furthermore, addition of additives such as fine aggregate, coarse aggregate, fillers, fibers, etc. can be carried out using conventional techniques.

Such multimodal spherical hydraulic cement compositions can be easily and suitably molded and cured by molding under relatively low pressures, or may of course be molded under high pressures, such as extrusion molding, press molding, injection molding, etc. It can also be formed by molding. In addition, when molding the multimode spherical hydraulic cement composition obtained in this way, if particularly high bending strength is required for the molded product (cured product) obtained, the cement composition may be molded throughout the entire body. Good mixing is preferred, for example it is desirable to mix the cement composition under high shear conditions. Here, when mixing under high shear conditions, it can be carried out using, for example, a Banbury mixer or a screw extruder, but it is also possible to use a twin roll mill and repeatedly pass the composition through the nip between the rolls. It is more preferable to apply a high shearing force to the mixture and mix it, and by this operation, the composition can be thoroughly mixed throughout, and the cured product obtained thereby can have a sufficiently high bending strength.

In addition, during curing, bars of reinforcing bars, synthetic resin bars, nonferrous alloys, or nonferrous metals (aluminum, etc.) may be added to the mixture of the cement composition, depending on the desired strength of the cement product (cured product). The reinforcing material may be provided by a known method, and furthermore, prestressing, chemical prestressing, etc. may be applied.

Additionally, to control the porosity properties of cement products, curing of the cement composition is performed under pressure, at least to the extent that the composition does not relax upon release of pressure (i.e., does not undergo substantial dimensional change upon release of pressure). It is advantageous to release the pressure after curing has progressed to a certain point. In this case, the applied pressure may be low, for example 3
It is sufficient if it is equal to or higher than M Pa. Furthermore, since the pressurization time depends on the type of hydraulic cement and the curing conditions (i.e., curing temperature and humidity), it is desirable to determine it in advance through a simple experiment.

Regarding the curing of the multimode spherical hydraulic cement composition, curing can be accelerated by performing the curing in a high temperature environment compared to the case where the curing is performed at normal room temperature. Even when carried out in an environmental environment, curing can be accelerated compared to the case of a conventional method. Therefore, in curing the cement composition, it is preferable to hold it in a humid atmosphere, preferably at or around 100% relative humidity, for about 0.5 to 28 days according to a conventional method. Furthermore, it is of course more preferable to cure under high temperature, high humidity, and high pressure.

A cement product (hardened product) obtained by curing such a multimode spherical hydraulic cement composition has excellent properties as described in (1) to (iii) below.

(1) Pores with a maximum dimension exceeding 15 microns account for less than 2% of the total volume of the product, and pores with a maximum dimension of 2 to 15 microns account for less than 5%, often less than 2%, of the total volume. Note that the proportion of such pores is measured by an absolute method of quantitative microscopy. That is, this method involves polishing one surface of a sample of a cement product to create a flat surface on the sample, cleaning the sample to remove polishing debris from the flat surface, and making holes in the polished surface form a flat surface on the sample. The polished surface is illuminated so that it is flush with the surface, and the plane is examined under an optical microscope (typically at a magnification of 10
0x) or by an electron microscope, and the dimensions are 15
This is a method of measuring holes larger than microns. (DeHo
ff and Rhines'"Quantitative"
MicroscopyJ McGraw Hil1
Note that in this case it is necessary to observe a sufficiently large sample surface in order to reduce statistical errors, and typically 100 holes are counted.

The sample is then further polished to reveal another (flat) surface and the examination by optical or electron microscopy is repeated. In this case, generally ten such surfaces are inspected. The total volume (including pores) of the cement product is also determined, for example, by the mercury displacement method and by measuring the external dimensions of the cement product.

(11) The distribution of pore sizes in the cement product is substantially uniform throughout the product.

(iii) The porosity of a cement product, that is, the ratio of the total volume of pores to the total volume of the product (including pores), is generally less than 20%, and can be as low as 15% or even 10%. The porosity is measured using the helium comparison pyranometer method to measure the volume of the product excluding pores, and the mercury displacement method and product external dimension measurement method to measure the total volume of the product including pores. It can be estimated by

Since the spherical hydraulic cement composition of the present invention is spherical and has multiple modes, even more synergistic close packing can be achieved, and the amount of water required during use is particularly reduced. The cement can be sufficiently cured with a small amount of water, for example, 30% by weight or less, preferably 15% by weight or less, more preferably 7% by weight or less, based on the weight of the spherical hydraulic cement in a dry state. In addition, by incorporating 0.1 to 100 parts by weight of processing additives made of various resins, the amount of water required is even lower, even though the amount of water required has been reduced due to the spheroidization and multi-mode nature of cement particles. Therefore, the cured product (cement product) obtained from this composition has particularly excellent bending strength. Furthermore, although various resins are blended as processing additives, the blending amount is 0.1 to 10%.
Since the amount is as small as 0 parts by weight, the obtained cured product has sufficient water resistance and fire resistance, and therefore functions satisfactorily as a noncombustible material. In addition, in the present invention, processing additives f) < 0, 1 to 1 are made of various resins.
By adding 10.0 parts by weight or even more modes, it becomes possible to further reduce the amount of processing agents made of various resins and the like. Since the amount of organic matter can be significantly reduced in this way, the resulting cement cured product has significantly improved heat resistance.

The multimode spherical hydraulic cement of the present invention is not limited to Portland cement, but can also be used with other cements such as alumina cement, white cement, early n cement, medium heat cement, ultra early strength cement, silica cement, blast furnace cement, and fried cement. Of course, it can be applied to ash cement, jet cement, high sulfate cement, seawater cement, oil well cement, as well as Toughrock, quicklime and other soil improvement materials, plaster, and waterproof cement.

It can be applied to all types of cement such as injection cement (including graft cement), acid-resistant cement, blast furnace slag, and fly annon.

"Example" Hereinafter, the present invention will be specifically explained with reference to Examples.

In addition, in the following examples, all units shown as "parts" shall mean "parts by weight" (Example 1) Cement clinker (Portland cement) was produced by a conventional manufacturing method. Cement clinker was calcined and melted (semi-molten) in a flame at 1500°C, then cooled and gypsum powder was added to obtain a spherical hydraulic cement.

The spherical cement particles thus obtained were classified into the following two components according to their particle sizes.

Particle size component ■: Passes through a sieve with an opening size of 125 μl, but 7
A component that does not pass through a sieve with an opening size of 6μ.

Particle size component ■; Particle classifier “J AlpineJ 100
Using MZR (trademark), a component consisting of particles with a particle size of 10μ
(within the μR range and 5μ shoulder from its peak).

Particle size component 080 parts and particle size component 2 thus obtained
20 parts were mixed and stirred to prepare a thoroughly mixed dry mixture. Next, this dry mixture was placed in a twin roll mill, and an aqueous gel consisting of 1.4 parts of oxypropyl methyl cellulose (Celacol HPM 15000) and 186 parts of water was added into the mill and thoroughly mixed at a constant speed. Then, the mixture obtained by mixing in the mill became a hard dough (like bread dough).

Next, this dough-like material was placed between two polyethylene terephthalate sheets and pressed with a hydraulic press to 3M.
Press and compress with the pressure of P a to a thickness of 0, 3 c+++
It was made into a sheet-like material.

The sheet-like body thus obtained was heated to a temperature of 18±2°C.
The mixture was allowed to stand for 7 days in a humid box with a relative humidity of 100%, and then left to stand for 7 days under atmospheric conditions to obtain a cured cement sheet.

The sheet-like hardened cement body thus obtained was cut to a size of 5. A large number of rectangular pieces having an OX of 1.7 (cm) were prepared, and a three-point bending test was conducted using the rectangular pieces as test pieces using an Instron testing machine.

In the test, the breaking load of the piece was measured with a span of 3.2 cm and a crosshead speed of 0.05 cm/min.

Moreover, the bending strength of the piece was calculated based on the following formula.

a = (1,5W L /d”w) X (0,10
1325/1.0332) [MP a] Here, W = Breaking load (kg) L = Nispan cm) d = Thickness (cm) W = Width (cx) σ = Bending strength (MPa) Test in this way When the bending strength of the piece was determined, the average value of 6 measurements was 60 MPa.

In addition, when the porosity of this cement sheet was investigated, it was found that 22
%, and virtually no pores with a maximum dimension exceeding 15 microns were detected.

Furthermore, for comparison, 080 parts of the above particle size component and 0 parts of the particle size component
A hardened cement body (cement sheet) was prepared by simply adding 133 parts of water to a dry mixture consisting of 20 parts, and the three-point bending strength of this was examined in the same manner as in the above example.
The average value of 6 measurements was 5 Q M Pa.

(Example 2) Calcium aluminate (Secar250, Lafar
ge) was spheroidized in the same manner as in Example 1, and the obtained spheroidized product was classified into particle size component (■) and particle size component (2) in the same manner as in Example 1, and further, 080 parts of particle size component and 020 parts of particle size component were separated. A dry mixture was prepared by mixing and stirring.

An aqueous gel consisting of 3 parts of oxypropylmethylcellulose and 12 parts of water was then added to 61 parts of this dry mixture. Hereinafter, 3 cement products were prepared in the same manner as in Example 1.
When the point bending strength was examined, a result of 60 soil 4 MPa was obtained.

Further, for comparison, a hardened cement body was prepared by simply adding 18 parts of water to the above dry mixture, and the three-point bending strength of this was examined, and it was found to be 40 MPa.

(Example 3) In place of the spherical Portland cement of Example 1, hemihydrous calcium sulfate cement was spheroidized in the same manner as in Example 1, and the obtained spheroidized product was subjected to the particle size component ■ and the particle size component in the same manner as in Example 1. (2) and further mixed and stirred 080 parts of the particle size component and 020 parts of the particle size component to prepare a dry mixture.

Next, 5 parts of polyacrylamide was added to 71 parts of this dry mixture.
An aqueous gel consisting of 1 part and 25 parts of water was added. Hereinafter, the three-point bending strength of the cement product was examined in the same manner as in Example 1, and a result of 62±5 MPa was obtained.

Further, for comparison, a hardened cement body was prepared by simply adding 30 parts of water to the above dry mixture, and the three-point bending strength of this was examined, and it was found to be 27 MPa.

(Example 4) Instead of the spherical Portland cement of Example 1, carunium aluminate cement (Sekar 71) was spheroidized in the same manner as in Example 1, and the obtained spheroidized product had the same particle size as in Example 1. The mixture was classified into component (1) and particle size component (2), and further, 080 parts of particle size component and 220 parts of particle size component were mixed and stirred to prepare a dry mixture.

Next, 7 parts of hydrolyzed polyvinyl acetate was added in a dry state to 100 parts of this dry mixture, and 11.5 parts of an aqueous gel containing 0.7 part of glycerol was further added to the resulting mixture.

The resulting composition is then mixed in a blade-type high-shear mixer and then removed in ground form from the mixer and passed repeatedly through the nip of a twin-roll mill to form a cohesive, continuous and homogeneous composition. A plate-like body was obtained.

Next, the obtained plate-shaped body was placed between polyethylene terephthalate sheets, heated at a temperature of SO'C, and pressed and compressed with a pressure of 3 MPa using a hydraulic press to a thickness of 0.3 atl. It was made into a sheet-like material. Then, polyethylene terephthalate is removed from this sorted body,
Leave it for 24 hours at 20°C, then heat it for 1 hour at 80°C.
The sheet was dried by heating for 5 hours.

When the properties of this cement sheet were investigated, the following results were obtained.

Bending strength: 185MPa Porosity
-0.5% or less Maximum dimension 15 μm or more Pore; 0.1% or less (Example 5) High alumina cement (Cimento Fondue) was used in place of the spherical Portland cement in Example 1 in the same manner as in Example 1. The resulting spheroidized product was classified into particle size component (■) and particle size component (2) in the same manner as in Example 1, and further, 080 parts of particle size component and 020 part of particle size component were mixed and stirred to prepare a dry mixture. .

Next, 7 parts of hydrolyzed polyvinyl acetate was added in a dry state to 100 parts of this dry mixture, and 11.7 parts of an aqueous gel containing 0.7 part of glycerol was further added to the resulting mixture.

Next, a cement sheet was produced by repeating the same operation as in Example 4, and the characteristics of the obtained cement/sheet were investigated, and the following results were obtained.

Bending strength: 180Mpa porosity
, 0.5% or less Pores with maximum dimension of 15 μm or more, 0.2% or less (Example 6) In place of the spherical Portland cement of Example 1, silicic acid [Snowcrete] 1 was used.
was subjected to spheroidization treatment in the same manner as in Example 1, the obtained spheroidized product was classified in the same manner as in Example 1, and further, 080 parts of the particle size component and 020 parts of the particle size component were mixed and stirred to prepare a dry mixture.

Next, 7 parts of hydrolyzed polyvinyl acetate in a dry state were added to 100 parts of this dry mixture, and 14 parts of an aqueous gel containing 0.7 part of glycerol were further added to the resulting mixture.

Next, a cement sheet was produced by repeating the same operations as in Example 4, and the characteristics of the obtained cement sheet were investigated, and the following results were obtained.

However, pressurization in a hydraulic press was for 30 minutes, and
The drying step at 0°C for 24 hours was omitted.

Bending strength: 105MPa Porosity
; 9.4% Maximum size: 15 μm or more pores; 0.2% or less (Examples 7 to 10) Calcium aluminate cement (Seven Curls 71) was used in place of the spherical Portland cement in Example 1 in the same manner as in Example 1. The resulting spheroidized product was classified in the same manner as in Example 1, and further 080 parts of particle size component and 20 parts of particle size component
A dry mixture was prepared by mixing and stirring the following parts.

Next, 5 parts of hydrolyzed polyvinyl acetate was added in a dry state to 100 parts of this dry mixture, and 1 part of water was added to the resulting mixture.
Added 2 parts.

Then, curing was performed under the following conditions to obtain cement sheets of Examples 7 to IO. However, in Example 8, 11
of water was added.

The curing conditions are as follows. In addition, in all Examples, the curing conditions of Example 4 were applied for parts not particularly described.

Example 7: After pressurizing and making into a nut shape and removing the pressure, 2
Leave at 0°C for 38 days.

Example 8: Same as Example 7, but left for 45 days.

Example 9: While heating at 20'C in a hydraulic press,
It was pressed into a sheet under a pressure of 3 MPa for 16 hours and then left at 20° C. for 35 days.

Example 10: Same as Example 9, but left for 45 days.

The properties of the cement sheet thus obtained are shown in Table 1.

Table 1 (Examples 11 to 19) Using the dry mixtures prepared in Examples 7 to 10, hydrolyzed polyvinyl acetate, glycerol, and water were added to 100 parts of this dry mixture in the proportions shown in Table 2, and then Mixed in a vane high shear mixer and sheeted in a twin roll mill as in Example 4.

Thereafter, the obtained sheet was heated in a hydraulic press at 50°C and pressed under a pressure of 5 MPa for 20 minutes,
Further, the cement sheets of Examples 11 to 19 were obtained by leaving them to dry for 15 days at 20°C1 relative temperature 50%.

The bending strength and bending modulus of the obtained cement sheet were examined, and the results are shown in Table 2.

Margins below Table 2 (Example 20) Using the dry mixture prepared in Examples 7 to 1o, add 50 parts of sand with an average diameter of 180 microns or less, 4 parts of hydrolyzed polyvinyl acetate, and water to 50 parts of this dry mixture. When 15 parts were added and the resulting composition was subjected to a capillary meter test, the following results were obtained.

Shear rate (1 part second) Shear stress (KN/am') 0
．． 245 0.00517245
0.009718 From the above results, the rate of change in shear stress was 92.0%.

Next, using the dry mixtures prepared in Examples 7 to 10, 50 parts of sand with an average diameter of 180 microns or less, 7 parts of hydrolyzed polyvinyl acetate, and 0 parts of glycerol were added to 50 parts of the dry mixture.
．． 6 parts and 8.0 parts of water were added, and the same operations as in Example 4 were repeated to prepare a cement sheet.The characteristics of the obtained cement sheet were investigated, and the following results were obtained.

However, in the drying step, the sheet was heated at 50° C. and pressed at 3 MPa for 10 minutes using a hydraulic press, and then dried at 50° C. for 15 hours.

Bending strength: 13QMPa Bending modulus: 46.50Pa Porosity
0.6% pores with maximum dimension of 15 μm or more,
Not detected (Example 21) Using the dry mixture prepared in Examples 7 to 10, 100 parts of this dry mixture was added with hydrolyzed polyvinyl acetate (Wanocar 30240; hydrolysis rate 77%, molecular weight 107,000).
) and 16 parts of water were added, and the resulting composition was subjected to a capillary rheometer test, and the following results were obtained.

Shear rate (1 part second) Shear stress (KN/cm') 0
．． 245 0.00608245
0.0120 From the above results, the rate of change in shear stress was 98%.

Next, using the dry mixtures prepared in Examples 7 to 10, 7 parts of hydrolyzed polyvinyl acetate (used in the above test examples), 05 parts of glycerol, and 8.5 parts of water were added to 100 parts of this dry mixture. Further, the same operations as in Example 4 were repeated to produce a cement sheet, and the properties of the obtained cement sheet were investigated, and the following results were obtained.

However, as a drying process, the above notebook was heated at 80 ° C and pressurized at 3 MPa for 10 minutes using a hydraulic press.
It was then dried at 80°C for 18 hours.

Bending strength: 121 MPa Bending modulus: 46.9 GPa Porosity
- 0.1% pores with maximum dimension of 15 μm or more, 0.2% or less For comparison, polyvinyl acetate with a hydrolysis rate of 99% and polyvinyl acetate with a hydrolysis rate of 46% are used as polymers blended in the above composition. Two separate tests were conducted using the same method as above except for the following tests.

For none, it was not possible to prepare a sufficient, ie, well-mixed, composition to perform capillary rheometer testing, nor was it possible to produce a cohesive sheet on a twin roll mill.

(Examples 22 and 23) Using the dry mixtures prepared in Examples 7 to 10, 100 parts of this dry mixture was added with hydrolyzed polyvinyl acetate (Example 5).
16 parts of water (Example 22) or 22 parts of water (Example 23) were added to prepare a cementitious composition.

To prepare the cementitious composition, hydrolyzed polyvinyl acetate and water were mixed in a Winkwer Sumpmer blade mixer under a vacuum of 73.5 cmHg, the vacuum was released, and the resulting mixture was mixed with the above mixture. add cement,
Further, the mixture was vacuumed again and mixed for 10 minutes.

The obtained dough was taken out from the mixer and rolled into a sheet by hand, and then the 7-sheet was heated at 20'C and a relative degree of 50%.
The mixture was left at 50'C for 15 hours, and then heated at 50'C for 15 hours.

The properties of the obtained sheet were as shown.

Example 23 Example 24 Bending strength +121 85MPa Bending modulus; 34.6 24GPa Porosity
34% 8.3% Pores with a maximum dimension of 15μI or more 0.5% 0.6% "Effects of the Invention" As explained above, the multimode hydraulic spherical cement of the present invention has a multimode particle size distribution structure. In the spherical hydraulic cement composition, 30 parts by weight or less of water is added to 100 parts by weight of the spherical hydraulic cement, and 0.1 to 100 parts by weight of various processing additives are further added. . Therefore, in this multimode hydraulic spherical cement composition, since the cement particles are spherical, there is less frictional resistance between the particles, and therefore, compared to conventional cement, it has a larger flow value at the same water-cement ratio. Of course, it has good fluidity and good filling properties (because it has good fluidity, it is possible to achieve close packing, and because it is multi-mode, it is possible to achieve even closer packing, resulting in an extremely dense cured product). In addition, by blending 0.1 to 10.0 parts by weight of processing additives made of various resins, the amount of water required can be further reduced by making the cement particles spherical and making them multimodal. In addition to this, it is also possible to reduce the amount of water required for the layer, and as a result, the hardened product (cement product) obtained from this composition has extremely excellent bending strength.

Furthermore, as mentioned above, in the cement composition of the present invention, by using spheroidized cement particles, close packing is possible and the amount of added water is reduced, and by making it multi-mode, it is possible to further promote close packing. In addition to significantly reducing the amount of added water, we also aim to reduce the amount of processing additives (water-insoluble or water-soluble, water-dispersible or non-water-dispersible) added through spheroidization, and furthermore, by making the layer multimodal. This makes it possible to reduce the amount of processing additives mentioned above. Further, if necessary, by mixing under high shear force, the bending strength of the cement product (hardened product) obtained can be greatly improved.

Furthermore, according to the present invention, the bending strength is 3 as described above.
A hardened cement product having a high bending strength of 0 MPa or more, or even 50 MPa or more, can be obtained, and as a result, the cement product can be produced with a high bending strength that does not exist in conventional cement products beyond the scope of the cement product market. products, such as plastics, steel, wood, and non-ferrous metals (aluminum and others) outside of the cement field.
This results in a cured product with a high bending strength that extends to the range of strength (bending).

Since the hardened cement product obtained in this way has high bending strength, it is possible to form this hardened cement product into a thin thickness, and it can be used with materials such as plastic, wood, steel, and non-ferrous metals (aluminum and others). This is a revolutionary new material that can replace

In addition, although various resins are blended as processing additives, the blended amount is small at 0.1 to 100 parts by weight, so the obtained cured product has sufficient water resistance and fire resistance. It functions sufficiently as a noncombustible material.

Claims (9)

[Claims] (1) A spherical hydraulic cement composition having a multimodal particle size distribution structure, which comprises:
0.1 to 10.0 parts by weight of at least one of water-dispersible processing additives, water-soluble processing additives, non-water-dispersible processing additives, and non-water-soluble processing additives are added. A multimodal spherical hydraulic cement composition characterized by: (2) A multimode spherical hydraulic cement composition according to claim 1, wherein 30 parts by weight or less of water is added. (3) The multimodal spherical hydraulic cement composition according to claim 1 or 2, wherein the water-dispersible processing additive includes cellulose ether derivatives, cellulose esters, amide-substituted polymers, polyalkylene oxide derivatives, and sulfonated substances. A multimodal spherical hydraulic cement composition, characterized in that it contains at least one of polyols. (4) The multimodal spherical hydraulic cement composition according to claim 1 or 2, wherein the water-soluble processing additive is a hydrolyzed vinyl acetate polymer or a copolymer thereof, or a hydrolyzed polyvinyl acetate polymer. A multimode spherical hydraulic cement composition, characterized in that it contains at least one of the following: (5) The multimodal spherical hydraulic cement composition according to claim 1 or 2, wherein the non-water-dispersible or water-insoluble processing additive includes polyethylene, fluororesin, polystyrene, phenol, polyvinyl chloride, A multimodal spherical hydraulic cement composition characterized in that at least one synthetic resin selected from polypropylene, acrylic, polyvinylidene chloride, epoxy, polyaramid, and furan is added. (6) The multimode spherical hydraulic cement composition according to claim 1 or 2, characterized in that at least one of additives consisting of fine aggregate, coarse aggregate, filler, and fiber is blended as an additive. A multimodal spherical hydraulic cement composition. (7) The multimode spherical hydraulic cement composition according to claim 6, wherein at least one of silica, olivine, titanium, and slate powder is blended as the additive. Composition. (8) The multimode spherical hydraulic cement composition according to claim 6, wherein the additive is an organic fiber selected from nylon, tetron, acrylic, propylene, aramid fiber, cellulose, raw silk, acetate, natural fiber, or steel fiber. , at least one inorganic fiber selected from glass fibers such as alkali-resistant glass fibers, ceramic fibers such as silicon carbide fibers, rock wool, and carbon fibers.
A multimodal spherical hydraulic cement composition characterized by incorporating seeds. (9) The multimode spherical hydraulic cement composition according to claim 6, wherein at least one of sand, gravel, and silica fue is blended as the additive.